According to the fluorescence correlation spectroscopy (FCS), a micro region in a determined specimen of a solution containing a fluorescent material at an extremely low concentration is irradiated with excitation light, the intensity of fluorescence generated in the micro excitation light irradiation region is detected, an autocorrelation function of a change over time in fluorescence intensity is calculated, and this autocorrelation function is analyzed to determine translational diffusion motion of the fluorescent material in the determined specimen (for example, refer to Patent Document 1).
A fluorescence correlation spectroscopy analysis device which analyzes a fluorescent material in a determined specimen by using this fluorescence correlation spectroscopy includes a confocal fluorescence microscope for excitation light irradiation and fluorescence detection and an analyzer which calculates and analyzes an autocorrelation function based on the intensity of fluorescence detected by the fluorescence microscope.
In Patent Document 1, multi-array detection using the fluorescence correlation spectroscopy is referred to. The multi-array detection referred to in this document is considered to detect fluorescence generated in each of a plurality of excitation light irradiation regions irradiated with excitation light and calculate and analyze an autocorrelation function for each excitation light irradiation region.
If simultaneous or successive determination of a plurality of excitation light irradiation regions is possible by means of fluorescence correlation spectroscopy as described in this document, for example, observation of interaction between molecules of protein or the like inside a cell as a determined specimen is considered to be allowed.
Patent Document 1: Japanese Examined Patent Publication No. 3517241